Felted product



high mechanical Patented Jan. 13, 1942 2,210,223 FELTED raonncr Paul Schlack, Berlin-Tre ptow, Germany, assignor,

by mesne assignments, to E. I. du Pont de Nemours and Company, Wilmington, Del.

No Drawing.

Serial No. 304,322.

1 Claim.

This invention relates to an improved felted product.

It has previously been attempted to substitute animal hairs and fibers in felted fabrics, felt for hats and felts for technical purposes wholly or partly by rayon or other synthetic filaments. These attempts had only a very limited success because the synthetic and artificial fibers possess as a rule insufiicient felting capacity and because they. lack the high elasticity, especially the high elasticity in the wet state, necessary for fulling. This elasticity is excellent for instance in fibers consisting of natural keratine.

It is an object of the invention to provide a new and improved felted product containing synthetic fibers.

A further object of the invention consists in the provision of a felt which does not lose its properties during the fulling treatment.

Further objects of the invention will become apparent from the detailed specification following hereinafter.

I have found that mixed felts of animal fibers and oriented highly elastic synthetic fibers of organic linear high polymers havingamide groups in the carbon chain, especially those consisting of relatively short structural units, are

exceptionally well suited for most purposes of the textile and mechanic art and by far surpass the known felts of cellulose artificial fibers for in stance rayon fibers and wool or also those of synthetic fibers consisting of vinyl polymers and wool. Even compared with felts of pure wool these mixed felts show advantages since as'a rule the polyamide fibers employed have a higher resistance to heat than wool. The resistance of such mixed felts against chemical influences.

that of feltsof pure wool or hair.

Synthetic fibers suitable for the production of especially against alkali and acid is greater than felts according to this invention may be spun.

from the superpolymers obtained by subjecting u-aminocarboxyl-ic acids or functional derivatives thereof for instance esters or urethanes. lactams, or diamines and dicarboxylic acids or functional derivatives of the latter-such. as esters or amides,

diisocyanates and diamines or diglycols. to polyamide-forming conditions.. Mixed condensation products of diamines. dicarboxylic acids and diglycols or amino acids, diamines, dicarboxyiic acids or diisocyanates, diamines, diglycols, amino Application November 14, 1939, In Germany November 26,

acids are also suitable. Especially suitable starting materials for the fibers are the polymeric anhydrides of fi-aminohexanoic acid and the similar polymerisates of e-caprolactam, as well as condensation products containing components having a carbon chain interrupted by hydrophii groups for instance ether groups, such as ppdiaminodiethylether or condensation products with relatively short structural units for instance lA-butylenediamine. Especially by hot ,fulling and acid fulling for instance in the presence of sulfuric acid and of softening agents or' swelling agents for either keratine or the polyamide fibers, such as formic acid, acetic acid, chloroacetic acid, alcohols, such as butanol, cresylglycol, extremely good felts are obtained which may still be improved upon by starting from crimped fibers or fibers which possess an uneven surface.

The fibers may be obtained according to the usual melt spinning processes. Especially suitable are fibers which are obtained by cutting or stamping cold drawn or cold rolled ribbons. In this case the cutting edges may be rovided with a wavy or toothed structure.

Example 1 A felt consists of per cent of a coarse wool of a single titer of 9 deniers and 40 per cent of a fiber of polymeric e-caprolactam of an individual titer of 8 deniers of a tenacity of 340 grams per deniers and an elongation before breaking of 60 per cent. The felt obtained by fulling at 60 C. in a bath containing sulfuric acid may be dyed uniformly and fastly with suitable acid wool dyestuffs.

Example:

A felt consists of '70 per cent of animal hair of a titer of 25 deniers and 30 per cent of a synthetic fiber of the polymeric anhydride of e-aminocaproic acid. The felt obtained by acid falling and by impregnating with a synthetic latex is suitable for technical purposes, for instance as an intermediate base for apparatus and machines or for such commodities as for instance felted cloths and hats.

I claim:

A sulfuric acid fulled felt comprising a mixture of animal fibers and cold drawn fibers of a. synthetic linear polyamide, said felt impregnated with synthetic latex.

PAUL SCHLACK 

